Integrated 3d metallizer

ABSTRACT

An apparatus and method for metallizing parts in an efficient manner. The apparatus includes a plurality of plates stacked together and spaced from one another in a manner that enables placement thereon of a plurality of part supports, which are affixed to the plates. Spindles are coupled to the part supports, wherein the spindles are configured to allow for rotation of the parts. The plates are also configured for rotation so that parts may be moved to a metallizer station and rotated at the metallizer station. The plates are supported by centered or offset plate supports. The part supports may be pins to which the spindles are coupled. The pins may be configured to rotate or the spindles may be configured to rotate on the pins. The stacked plates may be moved between a metallizer and parts loading and unloading stations in a convenient manner.

BACKGROUND 1. Field of the Invention

The present invention pertains to the field of metallizing devices.Specifically, this invention relates to a novel device, process andsystem for metallizing high volumes of plastic parts.

2. Discussion of Background Information

A. Background to High Volume Metallizing of Plastic Parts.

Technologies for metallizing plastic parts are well known. One commonmeans of metallizing plastic parts utilizes physical vapor deposition(PVD). PVD encompasses several methods for metal layer deposition,including sputtering, evaporation, cathodic arc deposition and others.For clarity, it is expressly understood that where the term “metal” isused, the term encompasses true metals and metallic compounds, such asTi_(x)N_(y), ITO, Al_(x)O_(y), Si_(x)O_(y), and Si_(x)N_(y), known toone of skill in the art to be applied via PVD.

Currently, the largest plastic part metallizing applications are onautomotive components and cosmetics products, such as lipsticks and nailenamel products. There is a large quantity of high-volume plasticpackaging components sold worldwide, mostly sourced in Asia, with someprograms using 10-30 million units per year. However, due to the typicalupcharge cost from these Asian manufacturers for metallizing, only thehigher end mass products and prestige products utilize metallizing. Ifcosts can be reduced, it will open the market for the metallization of asignificantly larger proportion of the plastic parts used in thepersonal care and cosmetics industries.

B. How Metallizing is Done Now

Existing systems designed to metallize small parts are based ontechnology that has been available for 40 years or more. A basic systemapplies a basecoat to the parts, applies a metal layer over thebasecoat, and applies a topcoat to protect the metal layer. Typically,the basecoat and topcoat are paint layers applied outside themetallizer.

There are many variations of this basic system. The foundation of apaint system is a conveyor that transports parts on spindles through thevarious paint stations. These conveyors are often of a chain-on-edgeconfiguration consisting of a series of chain links, much like a largebicycle chain, positioned on its side with pins extending from the chainlink hinge points. Often the pins will have the ability to rotate andwill have a rotation drive ring or sprocket causing the pin to rotatewhen engaged with a secondary drive chain located at key locations, suchas the spray booth. In some implementations, the paint systems used toapply the basecoat and topcoat spray the coating on the parts and thecoating is then dried or cured. Common drying and curing techniquesinclude air drying, thermal curing, and UV curing. Other paint systems,such as flow coating, are utilized more for trophies and other similaritems and do not lend themselves to caps and other components used inthe personal care and cosmetics industries.

Traditional metallizing lines cost approximately $ 3-5 million and takeup approximately 10,000 square feet of space. The state-of-the-art linesused by the best cosmetic metallizers in Europe and Asia typicallyinclude two UV cure paint lines and two six-foot cylindrical tankevaporative metallizers.

Within these systems, rods, which are rigid, linear devices, aresometimes used to consolidate parts into groups such that an entiregroup can be removed or placed on the conveyor by simply handling a rodrather than handling individual parts or spindles. Because the conveyorsin these systems are loaded and unloaded manually by operators, arod-based system reduces handling labor associated with moving partsbetween the conveyors and the metallizer since groups rather thanindividual parts are moved. Rods can be any length, however lengths of 1foot to 4 feet in length are common. For small parts, rod-based systemstypically utilize pins spaced at appropriate pitches to provide ahighest practical part density while providing for reliable mechanicalseparation and good coverage. Pitches in the range of every 1.25 inchesto 1.5 inches are common. Spindles and parts are mounted atop of thepins and are capable of individually rotating for spraying.

These lines typically process about 120 small pieces per minute (2 partsper second), with labor cost representing a significant portion of thevariable cost to run the lines and representing the majority of theprice difference between Asian and western European facilities. Here inthe U.S. there are few metallizing lines of this style. Therefore,pricing levels are substantially higher for cosmetic quality parts.

Existing metallizing systems utilizing a basecoat and a topcoat havebeen developed to maximize the visual appearance and durability of themetal coating. Small plastic parts are base-coated with a paint tosmooth out microscopic and visually detectable flaws in the injectionmolded plastic surfaces. During the last 15 years, near-cosmetic qualitymetallized parts have been produced without the use of a base-coat.However, these applications have only been successful with the use ofspecialized materials, highly polished well-maintained molds, and closeproximity of molding and metallizing.

Evaporation metallizers using aluminum are the simplest and leastexpensive types of vacuum metallizing machinery. The evaporatedconsumable is aluminum which is an inexpensive material that closelyresembles polished silver when metallized on a shiny substrate. Thinevaporated aluminum would not hold up well for most consumer productsand is over-coated with a transparent spray paint for that reason. Forparts that require a silver look, a clear paint is used. For a goldcolor the same paint can be tinted with dyes to achieve a gold look.Although virtually any color can be duplicated, silver and gold are byfar the two most common colors used to decorate packaging.

The most effective way to uniformly coat a small plastic part with paintto ensure a high quality end result is by the use of a spray line withfixed spray guns, where the parts rotate in front of the guns. Toshorten the length of the long coating lines, the use of UV cure paintshas been used. Although they often cost more than conventional paints,the reduction in floor space, and the improved quality and durability ofthe UV coatings justifies the higher cost per gallon.

Metallizers for evaporating or sputtering aluminum on small parts havetypically utilized cylindrical tank chambers ranging from 48 inches longby 28 inches diameter to 72 inches long by 72 inches diameter. Whilesmaller and faster batch systems with time saving load locks have servedwell for some simple configurations, existing systems utilizingcylindrical tank chambers to metallize small parts suffer from severaldrawbacks. For example, systems utilizing metallizers with smallerchambers have limited maximum system throughput, while systems utilizinglarger chambers experience long batch times and high system costs.

C. Problems and Limitations of Traditional Methodology.

There are numerous alternatives to PVD for applying metal coatings tosmall parts. One alternative technology is hot stamping, which utilizesa pressed on foil that is typically silver or gold metallic. However,while hot stamping commonly utilizes a custom die to create a band or apattern, such as specific artwork, full coverage of even the simplestpart geometries is not practical with this process. Another alternativedecorative technology that can utilize metallic foils is in-moldlabeling. However, in-mold labeling is not widely used because itgreatly increases the part molding tool costs and significantlylengthens the molding cycle time.

Silver reduction, such as is disclosed in Publication No. US20110155444,is another competitive technology that can coat an entire part surfacewith a metallic look. However, this process suffers from many of thesame issues of traditional metallizing such as high system costs, largefloor space requirements, reliance on volatile organic compounds (VOCs)for basecoats and topcoats, and the need for a technical staff to keepthe lines running and maintained. In addition, other specific downfallsof the silver reduction process include: the use of the precious metalsilver, rather than less expensive metals; the propensity of the silverto tarnish; the use of large amounts of water and high velocity air; theinability to properly cover more complex geometries; and a typicallyinferior surface finish.

Yet another non-PVD technology for covering a plastic part with a metalcoating is referred to as “electroplating” or “electro-less plating.”Advantages of this coating method include: generally high-qualitylooking films; the ability to quickly deposit thicker coatings, whichmay smooth out small surface imperfections in the plastic; and metalliccoatings that are mechanically and chemically superior to other“metallizing” processes. The disadvantages to the plating processesinclude: a limited number of plastic substrates, namely ABS and specialPP grades, are used for cosmetic decorative applications; parts need tobe submerged in a series of expensive aqueous “baths” that requireconstant supervision and maintenance by a technical staff; a limitednumber of commonly available metals; the heavier coatings of metal makea flexible cap inflexible; the racks supporting the parts can beexpensive; and the processing of racks through subsequent baths requiresconsiderable labor or automation.

In addition, existing PVD systems also have significant drawbacks. Thereare numerous problems associated with the typical metallizing systemsutilizing one or two large chambers and one or two accompanying paintlines. First, the substantial capital costs are prohibitive to mostindustries. In addition, even in industries where these systems are inplace, such as the cosmetics industry, the variable cost of running thesystem is very high, especially when compared against othermanufacturing alternatives such as specialty molding materials ordecorative technologies such as hot stamping. Traditional metallizinglines also consume an inordinate amount of floor space in comparison totypical molding and print decoration lines. As floor space costs gohigher the value proposition for a metallizing line decreases.Additionally, traditional metallizing lines require non-direct laborexpenses such as engineers, technicians, maintenance equipment, andtraining to keep them running.

Environmental concerns also weigh against these traditional metallizinglines due to the chemicals and solvents (VOCs) used in the associatedpaint systems. Growing compliance costs associated with use of thesechemicals is eroding the attractiveness of these systems.

In practice, the protection afforded by applying UV and other hard-coatsis often excessive. These topcoats were designed to ensure that themetal layer could withstand the substantial wear and tear resulting fromlong exposures to skin cremes, fragrances, and resistance to abrasion.Alternatives to UV and other hard-coats exist from industrial paintsuppliers, but the costs and benefits associated with these alternativesfor lower end personal care products do not differ significantly fromthe traditional methods. Further, even where alternative topcoats areable to reduce variable costs, the air-dry paint systems require largedrying ovens that add to the capital cost and occupy significant floorspace. In limited situations, such as with automobile parts, coatingsare being applied as an additional and separate process within thevacuum metallizer process chamber. However, while these in-chambercoatings show great promise to reduce costs, they have yet to be adaptedfor high-volume, low-end applications such as bathroom, household andpersonal care products.

Traditional metallizing processes have been difficult to automate due totheir batch-oriented design. Many batch metallizers can decorate 4000parts or more within a single batch with cycle times in the range of 20to 25 minutes. The large batch nature of these systems require two setsof racks, with one rack being loaded while the second is in process inthe metallizer. These racks are large in size and contain complexmechanisms to move parts in an orbital manner during the depositionsequence to assure coating uniformity. Part positioning for loading ofsuch racks is often unreliable, making automation of the processimpractical. Further, since the basecoat and topcoat systems are inlinecontinuous processes and the metallizer is a batch device, at least onecycle of work-in-process parts must be accumulated between the basecoatline and the metallizer and another between the metallizer and thetopcoat line. Often human operators manually remove parts and spindlesfrom the conveyors and place them on the metallizer rack, and thenremove parts from the metallizer rack and place them on the topcoatconveyor. This can be done individually or with groups of partspositioned on rods to reduce manual labor content. The combination ofcomplex and unreliable rack systems, large quantities of work-in-processbetween stations, and complex part motions makes automation of suchsystems problematic.

Manually loaded metallizers may utilize part racks to facilitate thesimultaneous metallization of multiple parts. However, these part racks,such as the part rack disclosed in U.S. Pat. No. 6,471,837 suffer fromseveral disadvantages. Most importantly, because these part racks arenot adapted for automated loading and unloading they require asignificant amount of manual labor. The use of manual labor increasesthe risk of part damage, which necessitates the use of base coats andtop coats to achieve an acceptable metal coating. Not surprisingly,known part racks are adapted to hold a relatively small number of partsat a very low part density. In addition, where rotation of individualparts is envisioned, the rotation mechanisms are quite crude, consistingof little more than a fixed rod that contacts the rack.

In addition to the scrap resulting from damage imposed as a result ofmanual loading and unloading, damage caused during upstream processessuch as molding or base coating are often not identified until aftermetallization is complete. The delay in identifying damaged parts stemsfrom the fact that metallizing exaggerates the presence of even smallblemishes. As a result, parts that seem of acceptable quality aftermolding or base coating are often unacceptable after metallizing. Wherelarge batch sizes are employed, large quantities of parts are placed atrisk, and large quantities of scrap can result. Automating the handlingof parts prior to metallization and eliminating conventional basecoatsare two ways to minimize the amount of scrap.

In systems where rods are employed, the parts being processed aretraditionally attached to a spindle, which acts as the connectionbetween the rod and the part. To withstand the aggressive spinning ofthe painting processes and roller coaster upside-down spins of thetraditional metallizing process, the connection between the spindle andthe part requires a firm grip. However, this firm grip leads to severaldrawbacks. A firm grip on the parts can cause part distortion andsubsequent fit and function issues. Engineering the appropriate firmgrip increases the complexity and cost of the spindles. In addition,although the firm grip is required to ensure the parts are not dislodgedduring processing, a firm grip makes for more difficult hand-offs of theparts from molding to metallizing and from metallizing to finalpack-out. Finally, in the event that the grip is not secure enough,parts will fall off spindles, which can cascade into a variety ofinefficiencies and even consumer related issues.

Falling parts frequently result in mechanical issues. In addition, acommon failure resulting from parts not being appropriately secured tothe spindles is contamination of spindles coated without parts, wherebyoverspray can secondarily contaminate or otherwise affect the next partthat goes on the un-cleaned spindle. These and other problems resultingfrom dislodged parts can have serious impacts on the quality of the endproduct and the performance of the metallizing system.

Significantly, traditional metallizing systems and methods lack theability to fully integrate the molding and metallizing operations forsmall 3D parts. Metallizing systems specific to CD and DVD manufacturingdid this 25 years ago, but such systems only apply metal coatings to a2D surface and are not designed to apply a coating to 3D parts. Withinthe last decade, automotive companies started utilizing integratedmetallizing and molding systems, but applications have been limited tolarge parts with low throughput rates.

None of the above existing devices, methods and systems, taken eithersingly or in combination, adequately address or resolve theaforementioned problems. Therefore, a need exists for a metallizationdevice, method and system that provides reliable, high-speedmetallization of a large volume of small parts.

SUMMARY OF THE INVENTION

The present invention solves the problems associated with metallizingsmall parts and provides an apparatus, method and system for applying ametal or metallic layer to small parts made from plastic, glass,composites, or other similar materials. The invention includes anapparatus for moving a plurality of parts in a metallizer. The apparatusincludes a plurality of rotatable plates stacked vertically and spacedfrom one another, wherein each plate has an outer perimeter, a pluralityof part supports arranged about the outer perimeter of each plate andone or more spindles arranged on one or more of the part supports,wherein each spindle is configured to removably retain thereon a part tobe metallized, and wherein each spindle is configured to enable rotationof the part removably retained thereon. The plurality of part supportsmay be pins extending from the plate and arranged about the outerperimeter thereof. In one option, each spindle includes a drive ringconfigured to engage a drive system for causing rotation of the spindleon the pin. In another option, each pin includes a drive ring configuredto engage a drive system for causing rotation of the pin and thespindle. Alternatively, the plurality of part supports may be clipsextending from the plate and arranged about the outer perimeter thereof.Each spindle includes one or more grasping rings. The apparatus includesa plate support structure for supporting the plurality of plates in avertical stack. The plate support structure may be a stack backbone anda plurality of stack support arms extending from the stack backbone andconfigured to support a corresponding number of the plurality of plates.The plate support structure may be a centered rod and the plurality ofplates each has a center port through which the centered rod passes, theapparatus further comprising couplings to couple the plates to thecentered rod. The plate support structure may be in the form of acentered cylinder and the plate may be in the form of curved stripscoupled to the plate support structure. The curved strip plates may beestablished as two or more segments and arranged about the plate supportstructure on substantially the same plane. The apparatus may furtherinclude a rotation unit arranged to cause rotational movement of thespindles on the plates. The rotation unit includes compliant drivefingers arranged for engagement of the rotation unit with the peripheryof the spindles.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1A shows a front view of a fixed stack.

FIG. 1B shows a detail front view of one row of the fixed stack depictedin FIG. 1A.

FIG. 2 shows a perspective view of the top of a stack of plates.

FIG. 3 shows a perspective view of the top of an unloaded stack ofplates.

FIG. 4A shows a detail front view of a plate utilizing fixed pins in theloaded and unloaded state.

FIG. 4B shows a detail front view of a plate utilizing rotating pins inthe loaded and unloaded state.

FIG. 5A shows a front view of a spindle loaded with a part.

FIG. 5B shows a front view of a spindle loaded with a part.

FIG. 5C shows a front view of a spindle loaded with a part.

FIG. 6 shows a detail perspective view of a plate utilizing clips.

FIG. 7A shows a perspective view of a plate loaded with parts. FIG. 7Bis a top perspective view of an embodiment of a portion of the apparatushaving a centered rod to which the stack of plates may be coupled. FIG.7C is a bottom perspective view of the apparatus portion of FIG. 7B.

FIG. 8A shows a side view of a separable stack.

FIG. 8B shows a side view of a support structure.

FIG. 9 shows a front view of a fixed stack.

FIG. 10 shows a front view of a stack located inside a metallizerchamber.

FIG. 11 shows a side view of the static rotation unit.

FIG. 12 shows a perspective view of the static rotation unit with themounting brackets removed.

FIG. 13 shows a plan view of an in-line metallizing system.

FIG. 14A shows a front view of a conveyor puck utilizing fixed pins.

FIG. 14B shows a front view of a conveyor puck utilizing rotating pins.

FIG. 15 shows a perspective view of one form of single point loaderutilizing two stacks.

FIG. 16 shows a plan view of a metallizing station of the presentinvention.

FIG. 17 shows a plan view of a metallizing station of the presentinvention.

FIG. 18 shows a plan view of one form of single point loader utilizingthree stacks.

FIG. 19 shows a perspective view of a separable stack

FIG. 20 shows a perspective view of one embodiment of a metallizingstation of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The device, method and system of the present invention allow users tometallize small parts with greater efficiency and at a throughput thatis significantly higher than existing methods. Specifically, the presentinvention utilizes a stacked arrangement of parts, which are all rotatedin a planetary manner during the metallizing process to ensure even andefficient coating.

As depicted in FIGS. 1A and 1B, the stack 100 of the present inventionis defined based on the location of the parts 10 being metallized. Theparts 10 are arranged in a series of substantially circular rows 2,whereby the entire stack 100 approximates the shape of a cylinder. Thehorizontal location of the parts 10 is set such that the axis ofrotation for each part 10 is located at a substantially constant radiusfrom the rotation axis of the entire stack 100. Preferably, the rows 2are each arranged in a manner to ensure that the parts 10 will beequally distributed vertically in the coating space. While there may besome deviation in the vertical position of the parts 10, there must beconsistency regarding the position of the vertical location of the driverings 30 associated with each spindle 20. Specifically, the drive rings30 in each row 2 must be at substantially the same vertical height, toensure proper mating between the drive ring 30 and the rotation drivesystem. Where larger parts 10 are utilized, or where the invention isdeployed for use in small metallizing chambers, there may be only onerow 2 of parts 10.

Turning to FIG. 2, the stack may be comprised of a plurality of plates104 that are stacked vertically. Once stacked, the collectionapproximates a cylinder as shown in FIG. 1A. As depicted in FIG. 3, eachindividual plate 104 is substantially round with a plurality of pins 150disposed near the circumferential outer edge of the plate 104. Theplates 104 need not be solid and may be hoops, curved strips, or otherforms that have a substantially round circumference. However, the plates104 are made of a rigid material, such that they do not bend while partsare loaded and unloaded or while the plate stack is processed in ametallizing unit.

As depicted in FIG. 4A, the pins 150 may be affixed to the plate 104such that the pins 150 cannot rotate or move in any way. This attachmentcan be done either through a press fit or through screwing, bolting,welding, or any other similar means. While the pins 150 are depicted ascylindrical, alternative shapes may be employed, provided the pins 150are sized to accept and securely hold a spindle 120. Alternatively, asdepicted in FIG. 4B, the pins 150 may be affixed to the plate in amanner that allows the pin 150 to rotate freely. In this embodiment, thepin 150 may simply fit in a hole in the plate 104, or it can utilize abearing or a bushing to facilitate rotation.

The spindle 120 fits over the pin 150 via a hole in the spindle base124. The depth of the hole in the spindle base 124 may vary based on thedesired placement of the spindle 120. In instances where it isadvantageous for the spindle 120 to rest directly on the plate 104, thehole in the spindle 120 is at least as deep as the height of the pin150. Alternatively, where it is advantageous to suspend the spindle 120such that the spindle base 124 is elevated above the plate 104, the holein the spindle 120 is shorter than the height of the pin 150.

In embodiments where the plate 104 utilizes fixed pins 150, the spindles120 fit loosely over the pins 150 in a manner that enables rotation ofthe spindle 120 about the pin 150. In embodiments where the plate 104utilizes pins 150 that rotate freely, the spindle 120 is fit to the pin150 in a manner that resists rotation of the spindle 120 about the pin150, such that rotation of the pin 150 results in simultaneous rotationof the spindle 120.

Parts 110 are attached to the top of a spindle 120. The part 110 andspindle 120 are mated in a manner that gravity, friction, spring, orsnap features prevent the displacement of the part 110 during transportand prevent the rotation of the part 110 about the spindle 120. Thearrangement of spindles 120 and pins 150 permits the stack of plates andthe parts 110 to rotate independently, creating a planetary movement ofthe parts 110, whereby the parts 110 rotate about their own axis whilethe entire circular array of parts rotates about the center of thestack.

Rotation of the parts 110 is accomplished through the incorporation of adrive ring 130. As depicted in FIG. 4A, the drive ring 130 may belocated on the spindles 120, where the fixed pins 150 are employed.Alternatively, as depicted in FIG. 4B, the drive ring 130 may be locatedon the pins 150, where the pins 150 rotate freely. While FIGS. 4A and 4Beach show the drive ring 130 as smooth, one will appreciate that thedrive ring 130 may possess teeth, knurls, or other serrations to assistin the secure integration of the drive ring 130 and the rotation drivesystem. Preferably, the drive ring 130 will extend beyond the perimeterof the plate 104 to facilitate engagement with the rotation drivesystem.

Turning to FIGS. 5A, 5B and 5C, variations of the spindles 120 of thepresent invention are depicted. The spindles 120 incorporate one or moregrasping rings 140 to facilitate manipulation of the spindles 120 byautomated handling machinery. However, depending on the requirements ofthe automated handling machinery, the spindles 120 may utilize a pair ofgrasping rings 140 as depicted in FIGS. 5A and 5B, or the spindles canutilize a single grasping ring 140, as depicted in FIG. 5C. Where twograsping rings 140 are used, the two grasping rings 140 will usuallydefine the upper and lower boundaries of a grasping zone 144. In thisconfiguration, the top grasping ring 140 has the added benefit ofshielding the grasping zone 144 from coating accumulation duringprocessing. The grasping ring 140 may function only to facilitatehandling or it may also function as a drive ring 130. Where the graspingring 140 is utilized as a drive ring 130, the grasping ring 140 willpreferably extend beyond the perimeter of the plate 104 and may possessteeth, knurls, or other serrations to assist in the secure integrationwith the rotation drive system. The spindles 120 depicted in FIGS. 5A,5B and 5C, are by way of example only and it is expressly understoodthat the spindles 120 may utilize a different shape depending on thespecific implementation and the grasping ring 140 and drive ring 130will be positioned in a manner to facilitate integration with automatedhandling equipment and the rotation drive system.

In some embodiments, the plates 104 may utilize holes instead of pins150 to hold the spindles 120. In these embodiments, the spindle base 124includes a protrusion that can be inserted into the hole in the plate104, thereby effecting a secure connection between the spindle 120 andthe plate 104 and enabling the spindle 120 to rotate about its own axis.

Turning to FIG. 6, the plates 104 may utilize clips 160 instead of pins150 to hold the spindles 120. The clips 160 are designed to mate withthe spindles 120 in a manner that securely holds the spindle 120, yetallows for rotation when the drive ring 130 is engaged by the rotationdrive system. While the clips 160 shown in FIG. 6 extend beyond theperimeter of the plate 104, the clips may be positioned in any mannerthat allows proper alignment of the parts 110. For example, the plates104 may include a cutout, and the clips 160 may be positioned such thatthe spindle 120 is held by the clips 160 at a position analogous to theposition of the pins 150. Preferably, a clip 160 is positioned above andbelow the plate 104, with the drive ring 130 located between the clips160 once the spindle 120 is inserted into the clips 160. However, clips160 may also be attached such that they are positioned entirely above orentirely below the plate 104. Regardless of the positioning of the clips160 with relation to the plate 104, however, preferably, the drive rings130 extend beyond the perimeter of the plate 104 to ensure properengagement with the rotation drive system.

FIG. 7A shows parts 110 loaded onto spindles 120 and multiple spindles120 loaded onto a plate 104 in preparation for metallizing. Parts 110are positioned around the circumference of the plate 104 and the plate104 is then stacked with other plates 104 in a vertical arrangement. Thenumber of plates 104 needed to create a full stack can vary. While thevertical height of the parts 110 being metallized and the size of themetallizing chamber determine the maximum number of plates 104 that maybe stacked, in some instances it may be advantageous to utilize fewerplates 104 in a stack. Preferably, the plates 104 are arranged in amanner to ensure that they will be equally distributed vertically in thecoating space. FIGS. 7B and 7C show an alternative version of each plate104, which includes a center port 105 and a plurality of cutouts 106.The apparatus includes a centered rod 107, which passes through thecenter ports 105 of the plates 104. The centered rod 107 is coupled toan actuator arranged to cause rotation of the centered rod 107. Theapparatus of FIGS. 7B and 7C further includes for each plate 104 acoupling collar 108 affixed to an underside of the plate 104 andarranged to engage with the centered rod 107 to removably retain theplate 104 on the centered rod 107 in a selectable position to permitstacking of the plates with sufficient spacing for parts placementthereon. The cutouts 106 are optional and may be incorporated to reducethe weight of the plate 104 and, therefore, the overall weight of theapparatus.

Plates 104 may be assembled into a fixed stack, where the stack isassembled in a manner such that the individual plates 104 may only beremoved by express disassembly. Alternatively, as depicted in FIGS. 8Aand 8B, individual plates 104 may be separable from the stack tofacilitate transport of the plates 104 during the loading and unloadingprocess. In both instances, the stack is supported by a supportstructure 290 and the plates 104 are held securely in place such thatthe entire stack may be rotated as a cohesive unit.

As depicted in FIG. 8B, a separable stack support structure 290 mayutilize a stack backbone 292 and plate mounting arms 294, which arestructurally sound for the loads they will bear. The support structure290 may also be adapted to create a fixed stack such that the plates 104are fixedly attached to the stack backbone 292, to the plate mountingarms 294, or both. FIG. 9 depicts an alternative arrangement, where thefixed stack utilizes plates 304 in the form of curved strips attached toa solid support structure 390. In addition to these specific examples,additional possibilities known to one of skill in the art for supportingthe plate stack of the present invention will determine the specificimplementation based on the style of plate used and the preference for afixed or a separable stack.

Returning to FIGS. 1A and 1B, the stack may not utilize plates at all.Instead, the stack may be created by arranging the parts 10 around thesupport structure 90. FIG. 1B depicts clips 160 attached directly to thesupport structure 90 as the means for holding spindles 20 and parts 10in correct alignment. One will appreciate that there are other similarmethods for securing spindles 20 such that the parts 10 being metallizedform a substantially cylindrical stack. For example, pins may be used inplace of clips 160 either by adapting the pin to attach directly to thesupport structure 90, e.g., using pins with a 90-degree bend, or byadapting the support structure 90 to provide an attachment point for thepins such that the pins are oriented substantially vertically.

Turning to FIG. 10, during metallization, the stack 400 is inserted intoa metallizing chamber 499. During metallization, the entire stack 400 isrotated about its axis, while the parts 410 are each rotated about theirindividual axes. To achieve the planetary motion of the parts 410, themetallizing chamber is fitted with a rotation drive system thatcomprises a static rotation unit 470.

Turning to FIG. 11, the static rotation unit 470 comprises a series ofcompliant drive fingers 472 and a mounting bracket 474. The compliantdrive fingers 472 are arranged in an arc with a radius approximately thesame as the outer radius of the stack 400. To ensure even coating, part410 rotation is required while the parts 410 pass through the processzone of the metallizer. Therefore, the compliant drive fingers 472 arearranged throughout the process zone, which is located in front of thecoating source 498. While the compliant drive fingers 472 may extendbeyond the process zone, part 410 rotation out of the process zonecauses needless frictional resistance to rotation of the entire stack400. Preferably, there is a sufficient number of compliant drive fingers472 in front of the coating source 498 to provide at least one fullrotation of each part 410 as the spindle 420 passes through the processzone.

The mounting bracket 474 shields the compliant drive fingers 472 and thedrive rings 430 from coating deposition and from thermal energy duringthe metallizing process. While the mounting bracket 474 is not required,its use reduces the need to clean the compliant drive fingers 472 andminimizes the risk that the compliant drive fingers 472 will losefunctionality as a result of constant bombardment from coatings duringthe coating process. Further, thermal energy accumulation on componentsin vacuum can result in high temperatures. Shielding reduces theresulting temperatures.

FIG. 12 depicts the compliant drive fingers 472 with the mountingbracket 474 removed. The compliant drive fingers 472 rotate the parts410 by engaging with the drive ring 430. Rotation of the stack 400causes the parts 410 to move through the coating zone. As the parts 410move through the coating zone, the free ends of the compliant drivefingers 472 engage with teeth, knurls, or other serrations located onthe periphery of the drive ring 430, causing the spindles 420 and theattached parts 410 to rotate as they traverse the arc in front of thecoating source 498.

The compliant drive fingers 472 are compliant to tolerate stack 400misalignment due to tolerance accumulation or an out of specificationcondition. These misalignments can be either vertical or radial and areparticularly important to account for in the metallization process giventhat the parts cannot be seen in that area of the metallizing chamber.As shown in FIG. 12, the compliant drive fingers 472 can be implementedas leaf springs, enabling a significant acceptance window in whichproper functioning occurs. However, a person of skill in the art willreadily appreciate that the compliant drive fingers may also beimplemented through any type of spring-loaded system or other compliantmeans. For example, a friction-based rub surface or a simple brush typesystem could perform a similar compliant drive function.

In some embodiments of the present invention, there may be multipleprocess zones to allow for the application of multiple coatings. Forexample, the metallizing chamber may be configured to apply a basecoatand or a topcoat in addition to depositing the desired metal or metalliclayer. In these instances, there must be sufficient complaint drivefingers 472 to ensure that the spindles 420 are rotated in each processzone. Preferably, there is a sufficient number of compliant drivefingers 472 to provide at least one full rotation of each part 410 asthe part 410 passes through each process zone.

While the stack of the present invention has the ability tosignificantly increase the processing rates for coating parts using astandard metallizer chamber, integrating the stack and rotation drivesystem of the present invention into an in-line metallizing system hasthe ability to substantially increase the production rate formetallizing parts compared to traditional in-line metallizing methods.For example, based on existing metallizer cycle times, the presentinvention has the ability to process more than 13,000 parts per hour, aproduction rate greater than currently available in-line metallizingalternatives by approximately a factor of four for similarly sizedparts.

In-line systems of the present invention may utilize a puck-styleasynchronous conveyor to move parts between processing stations, one ofwhich is the metallizer station. Additional available processingstations may include base coating, top coating, laser marking,inspection, component assembly, as well as others, depending upon thespecific need. Processing stations either stop the conveyor in a knownlocation for subsequent processing or perform a process while parts arein motion. The stop version of processing station, which utilizes theconveyor to move parts between processing locations and then stops at aknown location for processing, could include loading parts on spindlesat the molding machine, embossing, printing, laser marking, loading andunloading the stack of plates, or metallizing. The moving version ofprocessing station, which utilizes the conveyor to moves parts throughthe processing station at established rates for effective processing,could include painting, solvent flashing, curing, laser marking, orsurface pre-treatment.

The metallizing station is central to the in-line systems of the presentinvention and comprises a load point, which serves as an interface tothe conveyor, loading robotics, which load and unload parts to and fromthe plate stack, and a metallizer. Additionally, in some embodiments ofthe system of the present invention the metallizing station includesspecific design features incorporated into the metallizer to provide forsatisfactory operation of all metallizing and coating processes in situwithin the metallizer.

The part vulnerability window, which opens upon mold exit and closesupon completion of all coating and metallizing processes, is understoodas the period of time where parts are most susceptible to damage. Duringthe entire part vulnerability window, parts can be easily damaged fromdust, abrasion, human handling and many other factors. In typical batchoriented systems, parts have a significant part vulnerability windowthat can last many hours, and at times even much longer. The in-linesystems of the present invention, however, reduce the part vulnerabilitywindow to just a few minutes.

Turning to FIG. 13 the system of the present invention may incorporatean injection molding machine 602 and a metallizer 695 interconnected viaa conveyor 650. In this configuration, a mold take-out robot, which iscustomarily included with the injection molding machine 602, placesparts onto a conveyor puck at the puck loading station 606 for transportto the metallizing station 680 for in-line processing. As depicted inFIGS. 14A and 14B, the conveyor puck 622 comprises a stabilizing baseportion 626 that is adapted to accept one or more product specificspindles 620. Since the conveyor puck 622 is a transport mechanism forthe spindles 620, the conveyor puck 622 utilizes pins 624 or otherprotrusions designed to securely hold the spindles 620. To ensure smoothoperation of the system, the conveyor puck pins 624 mimic the plate 104pins 150. Similar to the plate 104 pins 150, the conveyor puck pins 624may be fastened to the conveyor puck 622 in a manner that prohibitsconveyor puck pin 624 rotation or the conveyor puck pins 624 may befastened to the conveyor puck 622 in a manner that permits the conveyorpuck pins 624 to rotate about their own axes. Alternatively, where theplates 104 utilize a hole rather than a pin 150, the conveyor puck 622may utilize a hole to accept a protrusion in the base portion of thespindle 620.

The conveyor pucks 622 depicted in FIGS. 14A and 14B are shown with twoconveyor puck pins 624, each conveyor puck pin 624 is adapted tosecurely hold a spindle 620. Utilizing two conveyor puck pins 624 perconveyor puck 622 presents certain advantages relative to reducedcomplexity and machine component count reduction and improves conveyorpuck 622 stability during transport on the conveyor 650. However, thedouble-pin conveyor puck design is but one means to accomplish parttransfer. The same could be accomplished where each conveyor puck 622utilizes a single conveyor puck pin 624 or where each conveyor puck 622utilizes more than two conveyor puck pins 624. Further, multipleconveyor pucks 622 can be assembled together forming a chain segment ofconveyor pucks 622 that is capable of bending and conforming as neededto straight and curved regions of the conveyor 650, the puck loadingstation 606 and the metallizing station 680. Alternatively, it ispossible to forgo the use of conveyor pucks 622 altogether and form achain of pins mounted to a flexible spline. As with the chain ofconveyor pucks 622 previously described, the flexible spline would bendand conform as needed to straight and curved regions of the conveyor650, the puck loading station 606 and the metallizing station 680.

Before the conveyor pucks 622 reach the molding machine load point 606,the conveyor puck pins 624 are holding spindles 620 that are empty,i.e., the spindles 620 are not loaded with parts 610. At the moldingmachine load point 606, the conveyor pucks 622 and empty spindles 620are arranged in a two-dimensional array such that the molded parts 610are placed on the spindles 620 by the molding machine robot or otherrelated device. The parts 610 remain on the spindles 620 throughout thecoating process, with the part 610 and spindle 620 mated in a mannerthat gravity, friction, spring, or snap features prevent thedisplacement of the part 610 during transport and prevent the rotationof the part 610 about the spindle 620.

As depicted in FIG. 14A, where fixed conveyor puck pins 624 areutilized, a drive ring 630 is located on the spindles 620, while, asdepicted in FIG. 14B, in embodiments where the conveyor puck pins 624rotate freely, a drive ring 630 may be located directly on the conveyorpuck pins 624. This arrangement mirrors the arrangement depicted inFIGS. 4A and 4B and permits an assembly of spindles 620 atop of conveyorpuck pins 624 and parts 610 atop of spindles 620, such that the parts610 can rotate as they pass through processing stations such as paintbooths, cure stations and other processing stations.

While multiple methods of rotating parts 610 on a conveyor 650 are knownin the art, one popular method is the use of one or more drive chainsthat are either fixed in place or actuated in either the forward orreverse direction. Drive chains may be arranged to interface with theconveyor pucks 622, causing rotation of the conveyor puck pins 624,spindles 620 and parts 610 as needed for the specific process performedas the parts 610 pass through a specific processing station. Preferably,the drive chain is actuated to provide control over the rotation speedof the parts 610 during processing. Examples of alternatives the drivechain include, a cogged belt, a smooth belt, or one or more rubberizedcords.

It is sometimes advantageous to align the parts 610 in a specificangular orientation. As is known in the art, there are several methodsto ensure proper angular orientation of parts 610. One such method isthe use of a D-shaped collar or ring. In systems of the presentinvention where proper angular orientation of the parts 610 is required,preferably a D-shaped collar or ring attached to either the spindle 620or the conveyor puck pin 624 to contact a bar as the conveyor travels,however, other methods known to persons of skill in the art may also beutilized to achieve proper angular orientation.

The conveyor 650 transports conveyor pucks 622, which have been loadedwith spindles 620 and parts 610 to the metallizing station 680 aspreviously described. When the conveyor pucks 622 reach the load point601, the conveyor pucks 622 are preferably arranged in a substantiallycircular arc in preparation for transfer of the spindles 620 to thestack. Once arranged, an automated handling device picks the spindles620 from the conveyor pucks 622 and transfers the spindles 620 asdescribed in more detail below.

In one embodiment of the present invention, all coating processes,including base coating, PVD, and top coating are applied in-situ at themetallizer 695. Upon metallizer exit, parts 610 are complete. In thisembodiment of the present invention, process consumables are minimizedand capital cost per part is at its lowest, creating a fully integratedprocess where parts 610 are metallized shortly after molding with only afew minutes of latency time and a very short part vulnerability window.As a result, defects associated with molding are evident immediatelyafter metallizing and the number of parts 610 at risk is minimized.

The metallizer 695 of the present invention is a vacuum metallizer.Appropriate metallizers are produced by multiple companies worldwide fordepositing metal and other types of coatings to a multitude of parts.Metallizers compatible with the present invention possess one or morecoating zones within the process chamber depending upon theirconfiguration. During metallization, parts 610 move about each coatingzone as the coatings are applied. A common size for the process chamberof the metallizers compatible with the present invention is a coatingvolume of 28 inches in diameter and 48 inches in vertical height(28×48). However, one will appreciate that the present invention canutilize metallizers with process chambers with larger or small coatingvolumes by adapting the dimensions of the stack.

The metallizer 695 may incorporate a single point loader 770 as depictedin FIG. 15. The single point loader 770 is an add-on option provided bythe metallizer manufacturers and consists of two single point loaderdoors 772 mounted on a 180-degree rotating platform 774. When one loaderdoor 772 is sealed in place on the metallizer 795, forming the fullyenclosed process chamber, the other loader door 772 is available forloading and unloading a stack 700 at the 180-degree position.

Basecoats may be applied prior to metallization for surface remediationand adhesion, and topcoats may be applied after metallization for metallayer protection, colored tints, and surface effects such as matte. Insome applications it may be useful to apply a basecoat or a topcoatoutside the metallizer 695. For example, certain industries, such as thecosmetics industry, commonly utilize both basecoats and topcoats appliedoutside the metallizer 695.

In one embodiment of the system of the present invention, a basecoatstation and a topcoat station are integrated as additional modules onthe same asynchronous conveyor system. The basecoat and topcoat stationscomprise spray booths, solvent flash-off zones, UV cure ovens, and otherperipheral equipment. While the basecoat station and topcoat station areboth preferably connected with the metallizer via the conveyor, in someimplementations, parts may be stored after molding and the conveyor maybe disconnected from the molding machine. Further, in someimplementations, the basecoat station, topcoat station, or both stationsmay be separated from the conveyor entirely.

The metallizing station contains all of the components necessary to loadand unload parts from the stack prior to and immediately following themetallizing process. The options for transferring spindles to the stackdepend highly on the chosen arrangement of the stack. Where a fixedstack is utilized, as in the configuration depicted in FIG. 16, a stacktransfer robot 775 transfers parts between the load point 701 and thefixed stack 714. Where the stack utilizes plates assembled into aseparable stack, a stack transfer robot 775 may transfer parts 710between the load point 701 and the stack in a manner similar to theprocess for the fixed stack, or automated handling equipment maytransport individual plates between the stack and the load point 701,where each plate is loaded and then transported back to the stack.

As depicted in FIG. 16, loading a fixed stack 714 according to thepresent invention utilizes at least one transfer robot 775. The stacktransfer robot 775 is positioned between the load point 701 in theconveyor 750 and the fixed stack 714. The load point 701 arrangesconveyor pucks 622, which have parts 610 on spindles 624, for loading.The stack transfer robot 775 possesses a plurality of pick and placefingers as are known in the art. Preferably, these pick and placefingers are positioned in pairs, creating a set of upper pick and placefingers and lower pick and place fingers, whereby one set of pick andplace fingers handles metallized parts 610 and the other set handlesunmetallized parts 610 during the loading process. Preferably, the loadpoint 701 mirrors the shape of the stack 714, permitting the stacktransfer robot 775 to load 180 degrees of parts 610 per transfer cycle.Although the term loading is used, the stack transfer robot 775 isresponsible for both loading and unloading. Preferably, the loading andunloading process occur simultaneously, but may occur in series.

The process of loading a fixed stack 714 that utilizes pins to holdspindles 620 can be fully automated to reduce part 610 handling andmaximize system efficiency. Starting from the condition where a fixedstack 714 of metallized parts 610 has just been removed from themetallizer 795, the load point 701 contains conveyor pucks 622 loadedwith unmetallized parts 610, and the stack transfer robot 775 is facingthe load point 701 with the upper pick and place fingers empty and thelower pick and place fingers empty and aligned with the spindles 620attached to the conveyor puck 622. The stack transfer robot 775 extendsthe lower set of pick and place fingers and grasps the spindles 620attached to the conveyor pucks 622 in the load point 701. The stacktransfer robot 775 then raises slightly, removing the spindles 620 fromthe conveyor pucks 622, and retracts the lower pick and place fingers.The stack transfer robot 775 then rotates so that it is facing the fixedstack 714 and raises or lowers to align its upper pick and place fingerswith a row of metallized parts 610. The stack transfer robot 775 thenextends its upper pick and place fingers, grasps the spindles 620holding the metallized parts 610, raises slightly to remove the spindles620 from the pins, and then retracts the upper set of pick and placefingers. The stack transfer robot 775 then raises slightly such that thelower pick and place fingers are aligned just above the fixed stack 714row that was just unloaded. The stack transfer robot 775 then extendsits lower pick and place fingers, lowers slightly, placing the spindles620 holding unmetallized parts 610 on the fixed stack 714 pins, andretracts the lower pick and place fingers while releasing the spindles620. The stack transfer robot 775 then rotates to face the load point701 and raises or lowers such that it's upper pick and place fingers arepositioned just above the empty conveyor pucks 622. The stack transferrobot 775 then extends its upper pick and place fingers, lowersslightly, placing the spindles 620 holding metallized parts 610 on theconveyor pucks 722, and retracts the upper pick and place fingers whilereleasing the spindles 620. Once the upper pick and place fingers areretracted, a full load cycle is complete, the conveyor pucks 622 areshuttled out of the load point 701, new conveyor pucks 622 containingunmetallized parts 610 enter the load point 701, and the cycle startsagain.

Alternatively, as depicted in FIG. 17, two load points 701 a and 701 bmay be utilized to facilitate the loading and unloading process. In thedual loading point configuration, conveyor pucks 622 with unmetallizedparts 610 are arranged in the first load point 701 a. Once theunmetallized parts 610 are removed from the conveyor pucks 622 asdescribed above, the empty conveyor pucks 622 shuttle to the second loadpoint 701 b and are replaced in the first load point 701 a with newconveyor pucks 622 holding additional unmetallized parts 610. Withregard to the operation of the stack transfer robot 775, the stacktransfer robot 775 picks the unmetallized parts 610 from the loadingpoint 701 a using the lower pick and place fingers as described above.The stack transfer robot 775 then rotates, picks the metallized parts610 from the fixed stack 714 using the upper pick and place fingers, andplaces the unmetallized parts 610 held in the lower pick and placefingers in the same manner described above. The stack transfer robot 775then rotates to face the second load point 701 b, which contains emptyconveyor pucks 622. The stack transfer robot 775 places the metallizedparts 610 on the empty conveyor puck 622 pins 624 and then retracts theupper pick and place fingers while releasing the spindles 620. Theconveyor pucks 622, which are now holding metallized parts 610 areshuttled out of the second load point 701 b, while the stack transferrobot 775 rotates to face the first load point 701 a and starts a newcycle of the loading process by picking unmetallized parts 610 from theconveyor pucks 622 located in the first load point 701 a.

The loading process is repeated as many times as necessary until theentire stack is loaded. However, since the stack transfer robot 775 isunable to load the entire circumference of the fixed stack 714 in onecycle, the fixed stack 714 must be rotated in order to complete theloading process. This fixed stack 714 rotation may occur at the end ofthe cycle described above, which would result in each row of the fixedstack 714 being loaded before the stack transfer robot 775 moves to loadthe next row, or the stack transfer robot 775 may repeat the cycle abovefor each of the rows in the fixed stack 714 prior to the fixed stack 714rotation, effectively loading the entire height of a portion of thecircumference of the fixed stack 714 prior to rotation. In eitherconfiguration, the fixed stack 714 rotation corresponds to the number ofspindles 620 that the stack transfer robot 775 is capable of handlingper cycle. Preferably, the stack transfer robot 775 is capable ofloading and unloading 180 degrees of the fixed stack 714 and the fixedstack 714 is rotated a corresponding 180 degrees to facilitate loadingand unloading the full circumference of the fixed stack 714.

Although this example recites the upper pick and place fingers handlingmetallized parts 610 and the lower pick and place fingers handlingunmetallized parts 610, a person of skill in the art will appreciatethat these assignments could easily be reversed and the stack transferrobot 775 movement adjusted accordingly. In addition, where the fixedstack 714 utilizes clips 160 as depicted in FIG. 6, the movement of thestack transfer robot would be modified such that spindles 120 areremoved from the clips 160 and inserted into the clips through extensionand retraction of the stack transfer robot 775 instead of through thevertical motion described above.

In implementations where additional speed is required, it is possible toutilize a single point loader 773 similar to the one depicted in FIG.18. In this configuration, the single point loader 773 comprises threemetallizer load doors 776 and three stacks 700(a-c). Adding anadditional stack 700 permits the separation of the loading process suchthat one stack transfer robot 775 a is dedicated to moving unmetallizedparts from conveyor pucks 622 located in the unmetallized part loadpoint 701 a to the stack 700 a, while a second stack transfer robot 775b is dedicated to removing metallized parts 610 from the stack 700 b andplacing them on conveyor pucks 622 located in the metallized part loadpoint 701 b. In this configuration, the stack transfer robots 775 a and775 b would preferably possess only one set of pick and place fingerssince each robot is dedicated to handling only metallized orunmetallized parts 610.

In one embodiment of the method for loading the stacks 700 using thesingle point loader 773 depicted in FIG. 18, a first stack transferrobot 775 a loads unmetallized parts 610 onto a stack 700 a by extendingthe pick and place fingers and grasping the spindle 620 attached to theconveyor puck 622. The stack transfer robot 775 a then moves verticallyto remove the spindles 620 from the conveyor pucks 622, retracts thepick and place fingers, and rotates to face the stack 700 a. Afteraligning the pick and place fingers with an empty row of pins, the stacktransfer robot 775 a extends the pick and place fingers, lowers thespindles 620 onto the pins, and retracts the pick and place fingerswhile releasing the spindles 620. The stack transfer robot 775 a thenrotates to face the unmetallized part load point 701 a to obtain thenext set of unmetallized parts 610. This series of steps is repeated,with the necessary rotation of the stack 700 a, until the entire stack700 a is loaded with unmetallized parts 610.

While the first stack transfer robot 775 a is loading unmetallized parts610 to the stack 700 a, a second stack transfer robot 775 b loadsmetallized parts 610 from a second stack 700 b. To unload the stack 700b, the stack transfer robot 775 b rotates toward the stack 700 b, andaligns with a row of metallized parts 610. The stack transfer robot 775b then extends its pick and place fingers, grasps the spindle 620, andmoves upward, removing the spindle 620 from the pin. The stack transferrobot 775 b then rotates to face the metallized part load point 701 b,lowers the spindles 620 onto the conveyor pucks 622, and retracts thepick and place fingers while releasing the spindles 620. This series ofsteps is repeated, with the necessary rotation of the stack 700 b, untilthe entire stack 700 b of metallized parts 610 is empty.

Once the stack 700 b of metallized parts is completely unloaded, theempty stack 700 a is completely loaded with unmetallized parts, and thestack 700 c in the metallizer completes processing, the single pointloader 773 is rotated such that the full stack 700 a of unmetallizedparts is placed in the metallizer 795, the empty stack 700 b is moved tothe unmetallized part loading point 701 a, and the stack 700 c of newlymetallized parts is moved to the metallized part load point 701 b.

Turning to FIG. 19, plates 804 may be configured into a separable stack800 that utilizes a stack backbone 892 and plate mounting arms 894.Reliable plate 804 engagement with the automated handling equipment andproper part 810 rotation in the metallizer depend upon accurate andrepeatable plate 804 location. One method for ensuring accurate andreliable plate 804 location utilizes datum pins 881. Datum pins 881 maybe located on the plate mounting arms 894, for engagement withcorresponding plate datum holes located in the plate 804. Active lockingfeatures may be implemented on the datum pins 881 to lock the plate 804into position such that it cannot be removed until an unlock feature isenabled. Alternate locking methods known to one of skill in the art,such as a locking method utilizing features in the backbone to form abayonet style lock, may be employed.

Turning now to FIG. 20, a separable stack 800 may be loaded using aprocess identical to the process described for loading a fixed stack,but a separable stack 800 also permits the removal of plates 804 fromthe stack 800 for direct loading at the load point 801. FIG. 20 depictsa loading setup for a separable stack 800, where the plates are removedfrom the separable stack 800 for loading and a plate transport robot 875is used to transfer the plates 804 between the separable stack 800 andthe plate staging point 802. In addition, a pick and place robot 870 isutilized to transfer the spindles 820 between the plate 804 and theconveyor pucks 822, which are located at the load point 801. Preferably,the plate transport robot 875 has an upper actuator 831 and a loweractuator 832, with the upper actuator 831 attached to an upper endeffector 834 and a lower actuator 832 attached to a lower end effector835. The upper actuator 831 and lower actuator 832 extend and retractthe upper end effector 834 and lower end effector 835, and the entireplate transfer robot 875 is capable vertical and rotational motion.

While the retrieval and placement of plates 804 can be done withoutfeedback of proper operation, it is reasonable to install feedback meansto interlock the various robot handling steps. Further, it is alsopossible to implement physical locking schemes on the plate mountingarms 894, the lower end effector 834, and the upper end effector 835.One way to achieve a locking scheme is to monitor the handoff processthrough the use of an optical sensor to validate proper plate 804position. Alternatively, proximity sensors could be mounted to the lowerend effector 834, the upper end effector 835, or both to monitor plate804 position. A successful handoff is verified by monitoring sensorstates throughout the handoff move. A handoff would sequence through thesensor on and off states in a pre-determined pattern, with a final stateindicating a successful handoff.

Plate 804 handling will work reliably if plates 804 are properly placedat their mounting positions. It is reasonable, therefore, to implementlocking means at the stack backbone 892, the plate mounting arms 894,the upper end effector 834 or the lower end effector 835 to immobilize aplate as required. Where additional security is required, lockingmechanisms may be employed at multiple locations. In addition, themounting arm datum pins 881 can be made in a manner where the datum pins881 can be actuated to lock the plate 804 into position. This lockingaction can be achieved with a bayonet type scheme or a two-partexpanding datum pin may be used. The locking or unlocking of plates 804on the plate mounting arms 894 can be done using mechanical, electricalor pneumatic actuation and is left as part of the design implementation.The plate 804 would be unlocked once the upper end effector 834 or lowerend effector 835 is in position to pick a plate 804. It would re-lockonce the plate 804 has been placed in position and validated to be atits proper location. In addition, the end effector datum pins 888, ifused, can also be locked or unlocked in a manner similar to the mountingarm datum pins 881. The end effector datum pins 888 would lock upon anup move into the plate datum holes. The end effector datum pins 888would remain locked until a plate 804 has been placed on the platemounting arm 894 at the separable 800 stack or at the plate stagingpoint 802.

During the separable stack 800 loading process, the plate transfer robot875 transfers plates 804 to the plate staging point 802, where the pickand place robot 870 then loads the spindles 820. A full cycle of theplate transport robot 875 begins when a plate 804 of unmetallized parts810 is attached to lower end effector 835, the plate transfer robot 875is facing the load point 801 and both the upper end effector 834 and thelower end effector 835 are retracted. The plate transfer robot 875 thenrotates to face the separable stack 800, and raises or lowers so thatthe upper end effector 834 is aligned with a plate 804 of metallizedparts 810. The upper end effector 834 is then extended into theseparable stack 800. If locking mechanism are used, the engagement ofthe upper end effector 834 with the plate as the upper end effector 834enters the separable stack 800 may be used to unlock the plate 804 fromthe separable stack 800. Once the upper end effector 834 is extended,the plate transfer robot 875 moves vertically, engaging the end effectordatum pins 888 with the plate datum holes. Once the end effector datumpins 888 are engaged, the plate transfer robot 875 continues to movevertically, lifting the plate 804 from the plate mounting arm 894, andthen retracts, removing the plate 804 from the separable stack.

Once the plate 804 of metallized parts 810 is removed from the separablestack 800, the plate transfer robot 875 moves vertically to align thelower end effector 835 with the plate mounting arm 894 vacated by theprior sequence of steps. The lower end effector 835 is then extendedinto the separable stack 800 and the plate transfer robot 875 lowers theplate 804 of unmetallized parts 810 onto the plate mounting arm, therebyengaging the plate mounting arm datum pins 881 with the plate datumholes. Once engagement is confirmed, the plate transfer robot 875 moveslower, releasing the plate 804, then retracts the lower end effector androtates such that the plate transfer robot 875 is facing the platestaging point 802.

Once the plate transfer robot 875 is facing the plate staging point 802,the robot aligns the lower end effector 835 with the plate 804 ofunmetallized parts 810 located in the plate staging point 802. The lowerend effector 835 is then extended to engage the plate 804 ofunmetallized parts 810 and, once the datum pins are secured, movesvertically to remove the plate 804 of unmetallized parts 810 andretracts the lower end effector 835. The plate transfer robot 875 thenaligns the upper end effector 834 with the plate staging point 802,extends the upper end effector 834, and lowers the plate 804 ofmetallized parts 810 into the plate staging point 802. Once the plate804 of metallized parts 810 is secured at the plate staging point 802,the plate transfer robot 875 retracts the upper end effector 834,returning the plate transfer robot 875 to the starting position.

A person of skill in the art will appreciate that there may beimplementations where it is advantageous to begin or end the separablestack loading process with less than a complete cycle of the platetransfer robot 875. In addition, the specific references to the upperend effector 834 and lower end effector 835 are for example only andthese roles may be swapped with a corresponding adjustment to themovements of the plate transfer robot 875.

While the plate transfer robot 875 is moving plates 804 between theseparable stack 800 and the plate staging point 802, the pick and placerobot 870 transfers spindles 820 between the conveyor pucks 822 and theplates 804. As depicted in FIG. 20, the pick and place robot 870 mayhave two arms 871 each possessing a plurality of pick and place fingers.Preferably, the arms 871 are shaped in an arc that approximates thecircumference of the plates 804. The arms 871 are arranged such that onearm 871 faces the plate staging point 802 and one arm faces the loadpoint 801. One step of the pick and place robot 870 cycle begins whenthe plate 804 of metallized parts 810 is placed in the plate stagingpoint 802, the plate 804 in the plate staging point 802 has been rotatedto a predetermined starting position, and the load point 801 is full ofconveyor pucks 822 holding unmetallized parts 810. Once activated, thepick and place robot 870 extends the pick and place fingers attached tothe arm 871 facing the load point 801 and the pick and place fingersgrasp the spindles 820 located on the conveyor pucks 822.Simultaneously, the pick and place robot 870 extends the pick and placefingers attached to the arm facing the plate staging point 802 and thepick and place fingers grasp the spindles 820 located on the plate 804.The pick and place robot 870 then moves vertically, simultaneouslyremoving the spindles 820 from the pins on both the conveyor pucks 822and the plate 804. Once the spindles 820 clear the pins, the pick andplace robot 870 rotates such that the arms 871 are reversed and thespindles 820 holding metallized parts 810 are now facing the conveyorpucks 822 and the spindles 820 holding unmetallized parts 810 are nowfacing the plate 804. The pick and place robot 870 then lowers thespindles 820 onto the conveyor pucks 822 and simultaneously lowers thespindles 820 onto the plate 804. Once the spindles 820 are secured tothe conveyor pucks 822 and the plate 804, the pick and place fingersretract and release the spindles 820. The conveyor pucks 822 are thenshuttled out of the load point 801 and replaced by conveyor pucks 822holding unmetallized parts 810, and the plate staging point 802 isrotated such that spindles 820 holding metallized parts 810 are facingthe pick and place robot 870 arm 871.

The configuration of the pick and place robot 870 arm 871 determines thenumber of steps required to load a full plate 804. Preferably, the arm871 is adapted to handle one half of the total number of spindles 820held on a plate 804, thereby limiting the loading cycle to two steps.However, additional steps may be utilized depending on the requirementsof the actual implementation. For example, if 120 degrees of parts areloaded, three steps are required. Once the plate 804 is fully loaded,the plate staging area 802 is rotated to its original starting positionin preparation for engagement with the plate transfer robot 875.

While the movements described pertain to embodiments where the spindles820 are attached to the conveyor pucks 822 and the plate 804 via pins,where the spindles 820 are secured using clips 160 as depicted in FIG.6, the movement of the pick and place robot 870 would be modified suchthat spindles 120 are removed from the clips 160 and inserted into theclips 160 through extension and retraction of the pick and place fingersinstead of through the vertical motion described above.

It is noted that the foregoing examples have been provided merely forthe purpose of explanation and are in no way to be construed as limitingof the present invention. While the present invention has been describedwith reference to exemplary embodiments, it is understood that thewords, which have been used herein, are words of description andillustration, rather than words of limitation. Although the presentinvention has been described herein with reference to particular means,materials and embodiments, the present invention is not intended to belimited to the particulars disclosed herein; rather, the presentinvention extends to all functionally equivalent structures, methods anduses.

What is claimed is:
 1. An apparatus for moving a plurality of parts in ametallizer, the apparatus comprising: a plurality of plates stackedvertically and spaced from one another, wherein each plate has an outerperimeter; a plurality of part supports arranged about the outerperimeter of each plate; and one or more spindles arranged on one ormore of the part supports, wherein each spindle is configured toremovably retain thereon a part to be metallized, and wherein eachspindle is configured to enable rotation of the part removably retainedthereon.
 2. The apparatus of claim 1, wherein the plurality of partsupports are pins extending from the plate and are arranged about theperimeter thereof.
 3. The apparatus of claim 1, wherein the plurality ofpart supports are clips extending from the plate and are arranged aboutthe perimeter thereof.
 4. The apparatus of claim 2, wherein each spindleincludes a drive ring configured to engage a drive system for causingrotation of the spindle on the pin.
 5. The apparatus of claim 2, whereineach pin includes a drive ring configured to engage a drive system forcausing rotation of the pin.
 6. The apparatus of claim 1, wherein eachspindle includes one or more grasping rings.
 7. The apparatus of claim1, further comprising a plate support structure for supporting theplurality of plates in a vertical stack.
 8. The apparatus of claim 7,wherein the plate support structure is a stack backbone and a pluralityof stack support arms extending from the stack backbone and configuredto support a corresponding number of the plurality of plates.
 9. Theapparatus of claim 7, wherein the plate support structure is a centeredrod and the plurality of plates each has a center port through which thecentered rod passes, the apparatus further comprising couplings tocouple the plates to the centered rod.
 10. The apparatus of claim 1,wherein the plurality of plates are substantially round.
 11. Theapparatus of claim 1, further comprising a plate support structure inthe form of a centered cylinder and wherein the plates are curved stripscoupled to the plate support structure.
 12. The apparatus of claim 11,wherein the plates are divided into two or more segments and arearranged about the plate support structure on substantially the sameplane.
 13. The apparatus of claim 4, wherein the drive ring includes aperiphery, the apparatus further comprising a static rotation unitarranged to cause rotational movement of the spindles, wherein thestatic rotation unit includes compliant drive fingers for engagementwith the periphery of the drive rings of the spindles.
 14. The apparatusof claim 13, wherein the compliant drive fingers are leaf springs. 15.An apparatus for moving a plurality of parts in a metallizer, theapparatus comprising: a plurality of plate segments stacked verticallyand spaced from one another, wherein each segment has an outer edge; aplurality of part supports arranged about the outer edge of each platesegment; and one or more spindles arranged on one or more of the partsupports, wherein each spindle is configured to removably retain thereona part to be metallized, and wherein each spindle is configured toenable rotation of the part removably retained thereon.
 16. Theapparatus of claim 15, wherein the plurality of part supports are pinsextending from the plate and are arranged about the perimeter thereof.17. The apparatus of claim 16, wherein each spindle includes a drivering configured to engage a drive system for causing rotation of thespindle on the pin.
 18. The apparatus of claim 16, wherein each pinincludes a drive ring configured to engage a drive system for causingrotation of the pin and the spindle.